Avoid emitting YAML back-references in kpt fn output

ts/kpt-functions/src/io.ts

@@ -38,6 +38,8 @@ const YAML_STYLE: DumpOptions = {
  skipInvalid: true,
  // unset lineWidth from default of 80 to avoid reformatting
  lineWidth: -1,
+ // avoid refs because many YAML parsers in the k8s ecosystem don't support them
+ noRefs: true,
 };
 
 /**

ts/kpt-functions/src/io_test.ts

@@ -15,7 +15,8 @@
  */
 
 import { FileFormat, parse, stringify } from './io';
-import { Configs, KubernetesObject } from './types';
+import { Configs, JsonArray, KubernetesObject } from './types';
+import { kubernetesObjectResult } from './result';
 
 describe('read', () => {
  describe('in YAML format', () => {
@@ -686,3 +687,68 @@ results:
  });
  });
 });
+
+describe('roundtrip', () => {
+ describe('using YAML', () => {
+ it('should not insert YAML references', () => {
+ interface Baz {
+ baz: number;
+ }
+
+ interface Foo extends KubernetesObject {
+ spec: {
+ array: Baz[];
+ };
+ }
+
+ const input =
+ 'items: [{apiVersion: v1, kind: Foo, metadata: {name: bar}, spec: {array: [{baz: 1}]}}]';
+ const configs = parse(input, FileFormat.YAML);
+
+ const foo = configs.getAll()[0] as Foo;
+ configs.addResults(
+ kubernetesObjectResult('something is wrong', foo, {
+ path: 'spec.array',
+ // Note: we re-use objects from the input to trigger YAML refs to normally be created
+ currentValue: (foo.spec.array as unknown) as JsonArray,
+ suggestedValue: (foo.spec.array.concat([
+ { baz: 3 },
+ ]) as unknown) as JsonArray,
+ })
+ );
+
+ const stringified = stringify(configs, FileFormat.YAML);
+
+ // We want to verify that there are no back-references like &ref and *ref in the output
+ expect(stringified).toEqual(`apiVersion: v1
+kind: ResourceList
+metadata:
+ name: output
+items:
+- apiVersion: v1
+ kind: Foo
+ metadata:
+ name: bar
+ spec:
+ array:
+ - baz: 1
+results:
+- message: something is wrong
+ severity: error
+ resourceRef:
+ apiVersion: v1
+ kind: Foo
+ namespace: ''
+ name: bar
+ file: {}
+ field:
+ path: spec.array
+ currentValue:
+ - baz: 1
+ suggestedValue:
+ - baz: 1
+ - baz: 3
+`);
+ });
+ });
+});

ts/kpt-functions/src/types.ts

@@ -403,13 +403,13 @@ export interface Result {
  */
 export type Severity = 'error' | 'warn' | 'info';
 
-interface JsonArray extends Array<Json> {}
+export interface JsonArray extends Array<Json> {}
 
-interface JsonMap {
+export interface JsonMap {
  [field: string]: Json;
 }
 
-type Json = null | boolean | number | string | JsonArray | JsonMap;
+export type Json = null | boolean | number | string | JsonArray | JsonMap;
 
 /**
  * Metadata about a specific field in a Kubernetes object.